Remove .regionCode

Not implemented by anyone and wasn't in the spec even before w3c/payment-request#955.

Author: saschanaz

api/PaymentAddress.json

@@ -531,54 +531,6 @@
           }
         }
       },
-      "regionCode": {
-        "__compat": {
-          "mdn_url": "https://developer.mozilla.org/docs/Web/API/PaymentAddress/regionCode",
-          "support": {
-            "chrome": {
-              "version_added": false
-            },
-            "chrome_android": {
-              "version_added": false
-            },
-            "edge": {
-              "version_added": false
-            },
-            "firefox": {
-              "version_added": false
-            },
-            "firefox_android": {
-              "version_added": false
-            },
-            "ie": {
-              "version_added": false
-            },
-            "opera": {
-              "version_added": false
-            },
-            "opera_android": {
-              "version_added": false
-            },
-            "safari": {
-              "version_added": false
-            },
-            "safari_ios": {
-              "version_added": false
-            },
-            "samsunginternet_android": {
-              "version_added": false
-            },
-            "webview_android": {
-              "version_added": false
-            }
-          },
-          "status": {
-            "experimental": false,
-            "standard_track": false,
-            "deprecated": true
-          }
-        }
-      },
       "sortingCode": {
         "__compat": {
           "mdn_url": "https://developer.mozilla.org/docs/Web/API/PaymentAddress/sortingCode",